The Crusades began with a rumor of defilement. In 1095, Pope Urban II denounced the Muslims as "a race utterly alienated from God." Among their many offenses, Muslims had seized the churches of Jerusalem: "They circumcise the Christians, and the blood of the circumcisions they either spread upon the altars or pour into the vases of the baptismal font." Such false rumors were already widespread in Christendom. Urban tapped them to launch the First Crusade.

Almost a millennium later, Muslim leaders and clerics are using the same language to stir the Muslim masses. They accuse the godless West of defiling the Prophet of God. Khaled Mashal, the leader of Hamas abroad, has demanded that Europe repent for the Danish cartoons. "Tomorrow, our nation will sit on the throne of the world. . . . Apologize today, before remorse will do you no good. . . . Since God is greater, and He supports us, we will be victorious." Iranian President Mahmoud Ahmadinejad struck the same note, in a speech marking the 27th anniversary of Iran's revolution: "The Iranian nation is telling you now that although you have Mammon, you do not have God. But God is with us."

"A race utterly alienated from God"--this is how Pope Urban II demonized the Muslims in the 11th century. This is exactly how Islam's leaders are demonizing the West in the 21st. The secular West had flattered itself, believing it had pulled the Muslim world into modernity. Yes, Islam has sent forth suicide bombers and terrorist insurgents. But they and their sympathizers were in the minority--so the pollsters and analysts told us: "Don't judge Islam by the acts of a misguided few." This faith in the pragmatic Muslim majority has underpinned every Western policy, from the Israeli-Palestinian "peace process" to the Bush administration's democracy promotion. The Muslim masses, the assumption goes, will choose peace and freedom, if given the chance. But they haven't. 9/11 could be attributed to a fanatic minority. Not so the Danish cartoon protests: Millions have taken part.

What about the Iranians who elected a president openly bent on confrontation with the West? What of those Egyptian voters who gave the Muslim Brotherhood a stunning success in parliamentary elections? And what about the supposedly secular Palestinians, who have swept Hamas into power? A poll conducted last year showed that 60 percent of Jordanians, Egyptians and Palestinians want Islamic shari'a law to be the sole source of legislation.

The experts resort to political and socioeconomic explanations: Syria incites proxies to punish Europe for its support of the U.S. over Lebanon. Iran stirs things up to escape possible sanctions over its nuclear program. Muslim minorities in Europe are protesting against racism and exclusion. Palestinians voted not for Islam, but against corruption.

There are plenty of inequalities in the world that cut against Muslims--enough to explain any outburst. This is the default analysis, reassuring us that there isn't a "clash of civilizations," only a clash of interests. These analyses have their place, but they're not sufficient. The clash goes beyond differing interests. Hundreds of millions of Muslims who live alongside us and among us inhabit another mental world.

Ahmadinejad feels the presence of the Mahdi, Islam's promised messiah. Hamas, according to its charter, believes that the Jews have fomented every upheaval in the world since the French Revolution. Muslim opinion-makers deny the thoroughly documented Nazi Holocaust, but accept the patently fraudulent Protocols of the Elders of Zion as an indisputable fact.

The present Muslim campaign has its share of opportunists. But it is also driven by a religious fervor. At some point, a Muslim equivalent of Pope Urban II could appear. This time, the crusade would be a Muslim one. Its advance scouts are already at work in Europe.

The West (and Israel) have mocked the prophet--not Muhammad, but Samuel Huntington, author of The Clash of Civilizations. Our elites have spent a decade denying the truth at the core of his thesis: that the Islamic world and the West are bound to collide. Even now, we glibly predict that possession of political power and nuclear weapons will make Islamists act predictably. It all makes perfect sense--to us. But the cartoon affair and the Hamas elections are timely reminders that our perfect sense isn't theirs.

Fortunately, it isn't too late. There is a clash of civilizations, but there isn't yet a war of the worlds. "You do not have God," they say. "God is with us." That is their prayer. But they lack power, resources and weapons. Today they burn flags; a united West can still deny them the means to burn more. It can do so if it acts swiftly and resolutely, to keep nuclear fire out of Iran's hands, and to assure that Hamas fails.

Martin Kramer is the Wexler-Fromer fellow at the Washington Institute for Near East Policy.

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